I have the D2, S9 & the J3, in addition to the newly purchased D3. To my ears, they all sound different, though the S9 & the J3 sound so alike as to be indistinguishable. The D3 beats them all in terms of SQ. That's about the only redeeming feature of the D3, however.

It's adequate as a movie player, though the app has an unfortunate propensity to freeze, requiring a pin through the reset hole. Oh yeah, I also can view MP4 videos straight on the D3 without converting, seeing that it has the decoding muscle to view 1080p files (supposedly - never tried any to be honest). Surprisingly, the screen does seem to lose out to the S9 & the J3 in terms of contrast and saturation, the AMOLED screen notwithstanding.

I have an S9, J3 and D3 and this is also my experience. D3 has the best sound IMO, though there's something about the screen doesn't live up to expectations.